source: MondoRescue/branches/3.2/mindi-busybox/miscutils/man.c@ 3186

Last change on this file since 3186 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
  • Property svn:eol-style set to native
File size: 7.1 KB
Line 
1/* mini man implementation for busybox
2 * Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com>
3 * Licensed under GPLv2, see file LICENSE in this source tree.
4 */
5
6#include "libbb.h"
7
8enum {
9 OPT_a = 1, /* all */
10 OPT_w = 2, /* print path */
11};
12
13/* This is what I see on my desktop system being executed:
14
15(
16echo ".ll 12.4i"
17echo ".nr LL 12.4i"
18echo ".pl 1100i"
19gunzip -c '/usr/man/man1/bzip2.1.gz'
20echo ".\\\""
21echo ".pl \n(nlu+10"
22) | gtbl | nroff -Tlatin1 -mandoc | less
23
24*/
25
26#if ENABLE_FEATURE_SEAMLESS_LZMA
27#define Z_SUFFIX ".lzma"
28#elif ENABLE_FEATURE_SEAMLESS_BZ2
29#define Z_SUFFIX ".bz2"
30#elif ENABLE_FEATURE_SEAMLESS_GZ
31#define Z_SUFFIX ".gz"
32#else
33#define Z_SUFFIX ""
34#endif
35
36static int show_manpage(const char *pager, char *man_filename, int man, int level);
37
38static int run_pipe(const char *pager, char *man_filename, int man, int level)
39{
40 char *cmd;
41
42 /* Prevent man page link loops */
43 if (level > 10)
44 return 0;
45
46 if (access(man_filename, R_OK) != 0)
47 return 0;
48
49 if (option_mask32 & OPT_w) {
50 puts(man_filename);
51 return 1;
52 }
53
54 if (man) { /* man page, not cat page */
55 /* Is this a link to another manpage? */
56 /* The link has the following on the first line: */
57 /* ".so another_man_page" */
58
59 struct stat sb;
60 char *line;
61 char *linkname, *p;
62
63 /* On my system:
64 * man1/genhostid.1.gz: 203 bytes - smallest real manpage
65 * man2/path_resolution.2.gz: 114 bytes - largest link
66 */
67 xstat(man_filename, &sb);
68 if (sb.st_size > 300) /* err on the safe side */
69 goto ordinary_manpage;
70
71 line = xmalloc_open_zipped_read_close(man_filename, NULL);
72 if (!line || strncmp(line, ".so ", 4) != 0) {
73 free(line);
74 goto ordinary_manpage;
75 }
76 /* Example: man2/path_resolution.2.gz contains
77 * ".so man7/path_resolution.7\n<junk>"
78 */
79 *strchrnul(line, '\n') = '\0';
80 linkname = skip_whitespace(&line[4]);
81
82 /* If link has no slashes, we just replace man page name.
83 * If link has slashes (however many), we go back *once*.
84 * ".so zzz/ggg/page.3" does NOT go back two levels. */
85 p = strrchr(man_filename, '/');
86 if (!p)
87 goto ordinary_manpage;
88 *p = '\0';
89 if (strchr(linkname, '/')) {
90 p = strrchr(man_filename, '/');
91 if (!p)
92 goto ordinary_manpage;
93 *p = '\0';
94 }
95
96 /* Links do not have .gz extensions, even if manpage
97 * is compressed */
98 man_filename = xasprintf("%s/%s" Z_SUFFIX, man_filename, linkname);
99 free(line);
100 /* Note: we leak "new" man_filename string as well... */
101 if (show_manpage(pager, man_filename, man, level + 1))
102 return 1;
103 /* else: show the link, it's better than nothing */
104 }
105
106 ordinary_manpage:
107 close(STDIN_FILENO);
108 open_zipped(man_filename); /* guaranteed to use fd 0 (STDIN_FILENO) */
109 /* "2>&1" is added so that nroff errors are shown in pager too.
110 * Otherwise it may show just empty screen */
111 cmd = xasprintf(
112 man ? "gtbl | nroff -Tlatin1 -mandoc 2>&1 | %s"
113 : "%s",
114 pager);
115 system(cmd);
116 free(cmd);
117 return 1;
118}
119
120/* man_filename is of the form "/dir/dir/dir/name.s" Z_SUFFIX */
121static int show_manpage(const char *pager, char *man_filename, int man, int level)
122{
123#if ENABLE_FEATURE_SEAMLESS_LZMA
124 if (run_pipe(pager, man_filename, man, level))
125 return 1;
126#endif
127
128#if ENABLE_FEATURE_SEAMLESS_BZ2
129#if ENABLE_FEATURE_SEAMLESS_LZMA
130 strcpy(strrchr(man_filename, '.') + 1, "bz2");
131#endif
132 if (run_pipe(pager, man_filename, man, level))
133 return 1;
134#endif
135
136#if ENABLE_FEATURE_SEAMLESS_GZ
137#if ENABLE_FEATURE_SEAMLESS_LZMA || ENABLE_FEATURE_SEAMLESS_BZ2
138 strcpy(strrchr(man_filename, '.') + 1, "gz");
139#endif
140 if (run_pipe(pager, man_filename, man, level))
141 return 1;
142#endif
143
144#if ENABLE_FEATURE_SEAMLESS_LZMA || ENABLE_FEATURE_SEAMLESS_BZ2 || ENABLE_FEATURE_SEAMLESS_GZ
145 *strrchr(man_filename, '.') = '\0';
146#endif
147 if (run_pipe(pager, man_filename, man, level))
148 return 1;
149
150 return 0;
151}
152
153int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
154int man_main(int argc UNUSED_PARAM, char **argv)
155{
156 parser_t *parser;
157 const char *pager;
158 char **man_path_list;
159 char *sec_list;
160 char *cur_path, *cur_sect;
161 int count_mp, cur_mp;
162 int opt, not_found;
163 char *token[2];
164
165 opt_complementary = "-1"; /* at least one argument */
166 opt = getopt32(argv, "+aw");
167 argv += optind;
168
169 sec_list = xstrdup("1:2:3:4:5:6:7:8:9");
170 /* Last valid man_path_list[] is [0x10] */
171 count_mp = 0;
172 man_path_list = xzalloc(0x11 * sizeof(man_path_list[0]));
173 man_path_list[0] = getenv("MANPATH");
174 if (!man_path_list[0]) /* default, may be overridden by /etc/man.conf */
175 man_path_list[0] = (char*)"/usr/man";
176 else
177 count_mp++;
178 pager = getenv("MANPAGER");
179 if (!pager) {
180 pager = getenv("PAGER");
181 if (!pager)
182 pager = "more";
183 }
184
185 /* Parse man.conf[ig] or man_db.conf */
186 /* man version 1.6f uses man.config */
187 /* man-db implementation of man uses man_db.conf */
188 parser = config_open2("/etc/man.config", fopen_for_read);
189 if (!parser)
190 parser = config_open2("/etc/man.conf", fopen_for_read);
191 if (!parser)
192 parser = config_open2("/etc/man_db.conf", fopen_for_read);
193
194 while (config_read(parser, token, 2, 0, "# \t", PARSE_NORMAL)) {
195 if (!token[1])
196 continue;
197 if (strcmp("MANDATORY_MANPATH"+10, token[0]) == 0 /* "MANPATH"? */
198 || strcmp("MANDATORY_MANPATH", token[0]) == 0
199 ) {
200 char *path = token[1];
201 while (*path) {
202 char *next_path;
203 char **path_element;
204
205 next_path = strchr(path, ':');
206 if (next_path) {
207 *next_path = '\0';
208 if (next_path++ == path) /* "::"? */
209 goto next;
210 }
211 /* Do we already have path? */
212 path_element = man_path_list;
213 while (*path_element) {
214 if (strcmp(*path_element, path) == 0)
215 goto skip;
216 path_element++;
217 }
218 man_path_list = xrealloc_vector(man_path_list, 4, count_mp);
219 man_path_list[count_mp] = xstrdup(path);
220 count_mp++;
221 /* man_path_list is NULL terminated */
222 /*man_path_list[count_mp] = NULL; - xrealloc_vector did it */
223 skip:
224 if (!next_path)
225 break;
226 next:
227 path = next_path;
228 }
229 }
230 if (strcmp("MANSECT", token[0]) == 0) {
231 free(sec_list);
232 sec_list = xstrdup(token[1]);
233 }
234 }
235 config_close(parser);
236
237 not_found = 0;
238 do { /* for each argv[] */
239 int found = 0;
240 cur_mp = 0;
241
242 if (strchr(*argv, '/')) {
243 found = show_manpage(pager, *argv, /*man:*/ 1, 0);
244 goto check_found;
245 }
246 while ((cur_path = man_path_list[cur_mp++]) != NULL) {
247 /* for each MANPATH */
248 cur_sect = sec_list;
249 do { /* for each section */
250 char *next_sect = strchrnul(cur_sect, ':');
251 int sect_len = next_sect - cur_sect;
252 char *man_filename;
253 int cat0man1 = 0;
254
255 /* Search for cat, then man page */
256 while (cat0man1 < 2) {
257 int found_here;
258 man_filename = xasprintf("%s/%s%.*s/%s.%.*s" Z_SUFFIX,
259 cur_path,
260 "cat\0man" + (cat0man1 * 4),
261 sect_len, cur_sect,
262 *argv,
263 sect_len, cur_sect);
264 found_here = show_manpage(pager, man_filename, cat0man1, 0);
265 found |= found_here;
266 cat0man1 += found_here + 1;
267 free(man_filename);
268 }
269
270 if (found && !(opt & OPT_a))
271 goto next_arg;
272 cur_sect = next_sect;
273 while (*cur_sect == ':')
274 cur_sect++;
275 } while (*cur_sect);
276 }
277 check_found:
278 if (!found) {
279 bb_error_msg("no manual entry for '%s'", *argv);
280 not_found = 1;
281 }
282 next_arg:
283 argv++;
284 } while (*argv);
285
286 return not_found;
287}
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